struct lsm_blob_sizes {
int lbs_cred;
int lbs_file;
+ int lbs_inode;
};
/*
#define __lsm_ro_after_init __ro_after_init
#endif /* CONFIG_SECURITY_WRITABLE_HOOKS */
+extern int lsm_inode_alloc(struct inode *inode);
+
#ifdef CONFIG_SECURITY
void __init lsm_early_cred(struct cred *cred);
#endif
static ATOMIC_NOTIFIER_HEAD(lsm_notifier_chain);
static struct kmem_cache *lsm_file_cache;
+static struct kmem_cache *lsm_inode_cache;
char *lsm_names;
static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init;
lsm_set_blob_size(&needed->lbs_cred, &blob_sizes.lbs_cred);
lsm_set_blob_size(&needed->lbs_file, &blob_sizes.lbs_file);
+ /*
+ * The inode blob gets an rcu_head in addition to
+ * what the modules might need.
+ */
+ if (needed->lbs_inode && blob_sizes.lbs_inode == 0)
+ blob_sizes.lbs_inode = sizeof(struct rcu_head);
+ lsm_set_blob_size(&needed->lbs_inode, &blob_sizes.lbs_inode);
}
/* Prepare LSM for initialization. */
init_debug("cred blob size = %d\n", blob_sizes.lbs_cred);
init_debug("file blob size = %d\n", blob_sizes.lbs_file);
+ init_debug("inode blob size = %d\n", blob_sizes.lbs_inode);
/*
* Create any kmem_caches needed for blobs
lsm_file_cache = kmem_cache_create("lsm_file_cache",
blob_sizes.lbs_file, 0,
SLAB_PANIC, NULL);
+ if (blob_sizes.lbs_inode)
+ lsm_inode_cache = kmem_cache_create("lsm_inode_cache",
+ blob_sizes.lbs_inode, 0,
+ SLAB_PANIC, NULL);
for (lsm = ordered_lsms; *lsm; lsm++)
initialize_lsm(*lsm);
return 0;
}
+/**
+ * lsm_inode_alloc - allocate a composite inode blob
+ * @inode: the inode that needs a blob
+ *
+ * Allocate the inode blob for all the modules
+ *
+ * Returns 0, or -ENOMEM if memory can't be allocated.
+ */
+int lsm_inode_alloc(struct inode *inode)
+{
+ if (!lsm_inode_cache) {
+ inode->i_security = NULL;
+ return 0;
+ }
+
+ inode->i_security = kmem_cache_zalloc(lsm_inode_cache, GFP_NOFS);
+ if (inode->i_security == NULL)
+ return -ENOMEM;
+ return 0;
+}
+
/*
* Hook list operation macros.
*
int security_inode_alloc(struct inode *inode)
{
- inode->i_security = NULL;
- return call_int_hook(inode_alloc_security, 0, inode);
+ int rc = lsm_inode_alloc(inode);
+
+ if (unlikely(rc))
+ return rc;
+ rc = call_int_hook(inode_alloc_security, 0, inode);
+ if (unlikely(rc))
+ security_inode_free(inode);
+ return rc;
+}
+
+static void inode_free_by_rcu(struct rcu_head *head)
+{
+ /*
+ * The rcu head is at the start of the inode blob
+ */
+ kmem_cache_free(lsm_inode_cache, head);
}
void security_inode_free(struct inode *inode)
{
integrity_inode_free(inode);
call_void_hook(inode_free_security, inode);
+ /*
+ * The inode may still be referenced in a path walk and
+ * a call to security_inode_permission() can be made
+ * after inode_free_security() is called. Ideally, the VFS
+ * wouldn't do this, but fixing that is a much harder
+ * job. For now, simply free the i_security via RCU, and
+ * leave the current inode->i_security pointer intact.
+ * The inode will be freed after the RCU grace period too.
+ */
+ if (inode->i_security)
+ call_rcu((struct rcu_head *)inode->i_security,
+ inode_free_by_rcu);
}
int security_dentry_init_security(struct dentry *dentry, int mode,
}
__setup("checkreqprot=", checkreqprot_setup);
-static struct kmem_cache *sel_inode_cache;
-
/**
* selinux_secmark_enabled - Check to see if SECMARK is currently enabled
*
static int inode_alloc_security(struct inode *inode)
{
- struct inode_security_struct *isec;
+ struct inode_security_struct *isec = selinux_inode(inode);
u32 sid = current_sid();
- isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
- if (!isec)
- return -ENOMEM;
-
spin_lock_init(&isec->lock);
INIT_LIST_HEAD(&isec->list);
isec->inode = inode;
isec->sclass = SECCLASS_FILE;
isec->task_sid = sid;
isec->initialized = LABEL_INVALID;
- inode->i_security = isec;
return 0;
}
return selinux_inode(inode);
}
-static void inode_free_rcu(struct rcu_head *head)
-{
- struct inode_security_struct *isec;
-
- isec = container_of(head, struct inode_security_struct, rcu);
- kmem_cache_free(sel_inode_cache, isec);
-}
-
static void inode_free_security(struct inode *inode)
{
struct inode_security_struct *isec = selinux_inode(inode);
- struct superblock_security_struct *sbsec = inode->i_sb->s_security;
+ struct superblock_security_struct *sbsec;
+ if (!isec)
+ return;
+ sbsec = inode->i_sb->s_security;
/*
* As not all inode security structures are in a list, we check for
* empty list outside of the lock to make sure that we won't waste
list_del_init(&isec->list);
spin_unlock(&sbsec->isec_lock);
}
-
- /*
- * The inode may still be referenced in a path walk and
- * a call to selinux_inode_permission() can be made
- * after inode_free_security() is called. Ideally, the VFS
- * wouldn't do this, but fixing that is a much harder
- * job. For now, simply free the i_security via RCU, and
- * leave the current inode->i_security pointer intact.
- * The inode will be freed after the RCU grace period too.
- */
- call_rcu(&isec->rcu, inode_free_rcu);
}
static int file_alloc_security(struct file *file)
struct lsm_blob_sizes selinux_blob_sizes __lsm_ro_after_init = {
.lbs_cred = sizeof(struct task_security_struct),
.lbs_file = sizeof(struct file_security_struct),
+ .lbs_inode = sizeof(struct inode_security_struct),
};
static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);
- sel_inode_cache = kmem_cache_create("selinux_inode_security",
- sizeof(struct inode_security_struct),
- 0, SLAB_PANIC, NULL);
avc_init();
avtab_cache_init();
struct inode_security_struct {
struct inode *inode; /* back pointer to inode object */
- union {
- struct list_head list; /* list of inode_security_struct */
- struct rcu_head rcu; /* for freeing the inode_security_struct */
- };
+ struct list_head list; /* list of inode_security_struct */
u32 task_sid; /* SID of creating task */
u32 sid; /* SID of this object */
u16 sclass; /* security class of this object */
static inline struct inode_security_struct *selinux_inode(
const struct inode *inode)
{
- return inode->i_security;
+ if (unlikely(!inode->i_security))
+ return NULL;
+ return inode->i_security + selinux_blob_sizes.lbs_inode;
}
#endif /* _SELINUX_OBJSEC_H_ */
static inline struct inode_smack *smack_inode(const struct inode *inode)
{
- return inode->i_security;
+ return inode->i_security + smack_blob_sizes.lbs_inode;
}
/*
}
/**
- * new_inode_smack - allocate an inode security blob
+ * init_inode_smack - initialize an inode security blob
+ * @isp: the blob to initialize
* @skp: a pointer to the Smack label entry to use in the blob
*
- * Returns the new blob or NULL if there's no memory available
*/
-static struct inode_smack *new_inode_smack(struct smack_known *skp)
+static void init_inode_smack(struct inode *inode, struct smack_known *skp)
{
- struct inode_smack *isp;
-
- isp = kmem_cache_zalloc(smack_inode_cache, GFP_NOFS);
- if (isp == NULL)
- return NULL;
+ struct inode_smack *isp = smack_inode(inode);
isp->smk_inode = skp;
isp->smk_flags = 0;
mutex_init(&isp->smk_lock);
-
- return isp;
}
/**
if (sp->smk_flags & SMK_SB_INITIALIZED)
return 0;
+ if (inode->i_security == NULL) {
+ int rc = lsm_inode_alloc(inode);
+
+ if (rc)
+ return rc;
+ }
+
if (!smack_privileged(CAP_MAC_ADMIN)) {
/*
* Unprivileged mounts don't get to specify Smack values.
/*
* Initialize the root inode.
*/
- isp = smack_inode(inode);
- if (isp == NULL) {
- isp = new_inode_smack(sp->smk_root);
- if (isp == NULL)
- return -ENOMEM;
- inode->i_security = isp;
- } else
- isp->smk_inode = sp->smk_root;
+ init_inode_smack(inode, sp->smk_root);
- if (transmute)
+ if (transmute) {
+ isp = smack_inode(inode);
isp->smk_flags |= SMK_INODE_TRANSMUTE;
+ }
return 0;
}
{
struct smack_known *skp = smk_of_current();
- inode->i_security = new_inode_smack(skp);
- if (inode->i_security == NULL)
- return -ENOMEM;
+ init_inode_smack(inode, skp);
return 0;
}
-/**
- * smack_inode_free_rcu - Free inode_smack blob from cache
- * @head: the rcu_head for getting inode_smack pointer
- *
- * Call back function called from call_rcu() to free
- * the i_security blob pointer in inode
- */
-static void smack_inode_free_rcu(struct rcu_head *head)
-{
- struct inode_smack *issp;
-
- issp = container_of(head, struct inode_smack, smk_rcu);
- kmem_cache_free(smack_inode_cache, issp);
-}
-
-/**
- * smack_inode_free_security - free an inode blob using call_rcu()
- * @inode: the inode with a blob
- *
- * Clears the blob pointer in inode using RCU
- */
-static void smack_inode_free_security(struct inode *inode)
-{
- struct inode_smack *issp = smack_inode(inode);
-
- /*
- * The inode may still be referenced in a path walk and
- * a call to smack_inode_permission() can be made
- * after smack_inode_free_security() is called.
- * To avoid race condition free the i_security via RCU
- * and leave the current inode->i_security pointer intact.
- * The inode will be freed after the RCU grace period too.
- */
- call_rcu(&issp->smk_rcu, smack_inode_free_rcu);
-}
-
/**
* smack_inode_init_security - copy out the smack from an inode
* @inode: the newly created inode
struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
.lbs_cred = sizeof(struct task_smack),
.lbs_file = sizeof(struct smack_known *),
+ .lbs_inode = sizeof(struct inode_smack),
};
static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(bprm_set_creds, smack_bprm_set_creds),
LSM_HOOK_INIT(inode_alloc_security, smack_inode_alloc_security),
- LSM_HOOK_INIT(inode_free_security, smack_inode_free_security),
LSM_HOOK_INIT(inode_init_security, smack_inode_init_security),
LSM_HOOK_INIT(inode_link, smack_inode_link),
LSM_HOOK_INIT(inode_unlink, smack_inode_unlink),
projects / linux.git / commitdiff